Centrifugal fan



Dec. 9, 1

A. F. ROTH CENTRIFUGAL FAN- Filed May 31. 1923 INVENTOR ova; @L awm BY 3Ma ATTORNEY Patented Dec. 9, 1924.

units mac-tern n. 30TH, or NEW-Ann, nawunas-nn.

CENTEIFUGAL Application filed-May 31,

Ton whom it may concemp citizen of the United States; and a.residentof:Newark, inthe county ot Essex and State of New Jersey, have inventedcertain new and useful; Improvements" in a. Centrifugal Fan, otlwhichthe following is a full, clear, and exact specification.

This. invention relates more I particularly to a-class of'devicesadapted to be usedifor circulating air.

My invention hash-tor 'its object} primarily to provide a. fan.designedto 1 be employed? in factories, restaurants, halls, buildingsand elsewhere for maintaining healthful atmospheric conditions by.causing efiectual ex haustion oithe. air. whencharged withexcessiverheat, smoke, gaseous or acid' fumes and other impurities aswellas adapted for circulating air for cooling. purposes and torcirculating radiated hot air for heating purposes; The. fanJmay; also:be useda-js an'air blower, and. is. adapted to. be. centrifugallydriven by windior an-y 'suitable power; such asan electric motor, thefan being-of a form serving to prevent contact of the exhausted air.with. the motor-to overcometendencyto prenviatiurely damage the. partsthereof.

The invention contemplates mainly the provision; of a: surface, elementor flat disk which serves asa baiile andyprotector, and thiselenientshas aicentralhub. portion which may be mounted-Eon thewshaft ofan electri-- callydriven motor; or ot'he-ri power: Fixed on one. faceoftthe. surfacerelement surround ing its hubl portion are spacedradially disposed'sets'otair suction elements or blades, eachseticonaposedloffa multiple: of spaced members, andthe members" of eachset of the blades. are. bent substantially similar to the curvature ofatubeor cone, while the outermost parts of. the edges. offithe ends ofeach set of the blades are taperedtoward the centers lengthwise-thereofas well-as tapered toward the hub portion of: the surface element; Whenthe; fan is driven theair currents; caused? by the blades will bebackstopped by the battlev surface element, and the air currents willtend: to be received in the inner endsuof' theblades for discharge inhelical currents throughthe outer ends ofthe blades; The tendency tostatic pressure-ofitlie air currents-at the hub portion otthesurfaoeelement will thereby be prevented and elfectual atmosphericcirculation 1922. Serial No. 842,522:

will be accomplished whether" the fan is driven at a slow or tast'speedA further object or the invention islto provide a centrit'ugalfah of asimple; "etf'rcient. and durable construction which may be made in anyappropriate size and shape.

With these and other objects in View the inventionwill behereinattermore 'fiulyeaplained with reference to the accompanyingdrawing formingapart of this specification in which similar characters of referenceindicate corresponding parts in all the views, and will then be pointed.out in the claims at the end oil the description.

In the drawing Figure i'is a front'elevaticn of one form otcentri'fugal'fan embodynigv my invention.

Fig. 2 is an enlarged. fragmentary view showing a side elevation of thefan' applied toan electric motor as well as showingthe manner of its usefor exhausting air.

Fig. .3 isv an enlarged front-elevation ot an assembled set of theblades used in the fan.

Fig. 4 is an enlarged plan of the blank from which one ofthe blades istormech and Fig. 5 is anenlar'ge'dpjlan ofthe blank from whichthe secondblade is formed.

The .fanhas a su-riace element or flat disk or plat-e which may be otanyappropriate shape andsize, though the disk isjpreferab'ly circular withahub. portiony a's'lll in its cent'ralpart, .a-ndin practice the hub.portion of the-surface element or disk; 10 may. be mounted on the.shatt,as 12, of'an electric. motor, is-13,01 other suitab'le powerdriving means whereby the. disk will becentrit'ugally. driven. I

On the faceof thedisk 1Q opposite the shaft 12 may be one or a number otsetsol multiple or.v pairs of air suction elements or: blades, as 14. Inthe. drawing shown a form of th e an .liavi'ng fcursetso'r pairs of theblades, all of which are o1 similar formatiQna-and these blades arearranged equi distant apart surrounding the hub, portion 11 of the diskas well as being" disposed radially. relative to the hub portion.

Each set-oi the blades 14 may be. in pairs, as shown, to include aninner member 15 and an outer member 16'spacedfrom the inner member, andeach :member of 'each pair of'bladesis formed from a blank, as 17. whichmay be of pliable sheet metal; The blanks otthe inner members 15 of theblades are smaller than the blanks of the outer members of the blades.Each of the blanks is approximately triangular in shape having tworight-angled straight edges, as 18, 19, while the inclined edge of eachblank may be outwardly curved, as at 20, and one of the corner portionsof each blank may be cut away transversely, as at 21, in parallelrelation to the straight edge 19 of the'blank. Each blank of the membersof each pair of the blades is bent so that the part at the edge 21overlaps the central portion of the straight edge 19 to provide eachblade with curved surfaces corresponding to the curva t-ureof thesurfaces of a tube or split tube so that the blades will be of forms fortaking currents of air with minimum resistance. The walls of the membersof each pair of the bladesare thereby substantially cone-shaped orcylindrical, and by curling the blank of each member of each pair ofthe'blades with the edge 21 lapping upon the edge 19, portions of theedges of the open ends of each member are tapered as at 22, 23, towardthe center .of the length of the blade. Each pair of the blades areassembled with the in ner member 15 being inserted within the outermember 16, and the inner members of the blades being smaller than theouter members, the tapered parts of the members of each blade are spacedapart, as shown.

The sets of blades are arranged on the disk 10 with the outer faces ofthe triangled edge parts of the outer members of the blades lying uponthe disk, and the sets of blades are also arranged with the trianglededges of the members of the blades being in spaced parallel relation incruciform fashion surrounding the hub portion. The tapered parts of themembers of the'blades are thereby disposed outermost from the disk, andthe axes of the cylindrical or coni-' cal blades are substantiallytangential to the hub portion. The blades may be secured to the disk byriveting or otherwise fastening, as at 24:, the overlapping edge partsof the members of each blade to the disk, and the outer members 16 ofthe blades may be connected by means of a ring or band, as 25, havingspaced parts riveted, as at 25*, to each of the outer members, in orderto reinforce the blades against tendency to swerve from their normalpositions when under the pressure of suctional air-currents during theoperation of the fan.

The fan may be employed in any suitable manner in factories,restaurants, buildings, cars, boats and elsewhere for producing sanitaryatmospheric conditions by exhausting the air when charged with excessiveheat, smoke, gaseous or acid fumes and other impurities as well as beingadapted for cooling purposes and for circulating radiated hot air forheating purposes or the fan may be used as an air blower. In the drawingis illustrated the employment of the fan for exhausting purposes, andwherein the fan with the shaft 12 and motor 13is mounted in spacedrelation to the outlet end, as 26,

of a tubular duct or hood, as 27, which may lead from the place orlocality from which air is to be exhausted. The fan is also arranged sothat the blades 14 are in opposition to the outlet of the hood, and whenthe fan is driven by the operation of the motor the air-currents fromthehood will be suctionally drawn by the inner ends of the members ofthe blades for passage through the outer ends of the blades and thecurrents of air will be admitted in spiral currents from the hub portionof the disk for passage and discharge through all members of the blades.The tendency to static'air pressure prevailing at the hub will therebybe prevented, and the disk 10 serving as a baffle for receiving thecurrents of air provides unusual efficiency in the operation of the fanwhether driven at low-or fast speeds, the disk also serving as aprotector for the motor against liability to damage by contact with Ythe exhausted currents of air. 90

In the foregoing description, I have em bodied the preferred form of myinvention, but I do not wish to be understood as limiting myselfthereto, as I am aware that modifications maybe made therein withoutdeporting from the principle or sacrificing any of the advantages ofthis invention, therefore, I reserve to myself the right to make suchchanges as fairlyfall within the scope thereof.

Having thus described my invention, I- claim as new and desire to secureby Letters Patent 1. centrifugal fan, comprising a baffle surfaceelement with a hub portion, a

plurality of sets of spaced interfitting airsuction elements fixed onone face of the surface element surrounding the hub portion andeachair-suction element including spaced inner and outer members, and themembers of each pair of said air-suction elements curved approximatelysimilar to the curvature of a tube, and allof the air suction elementsbeing disposed radially relative to the hub portion of the surfaceelement whereby the axes of said members are substantially tangential tothe hub portion, the outer parts of the edges of the ends of the membersof each pair of the air-suction elements being tapered toward thecenters each air-suction element including spaced inner and outermembers, the members of each pair of said air-suction elements havingwalls curved approximately similar to the curvature of a slitted tubeand the edges of the slits eing fastened to the surface element wherebyall of the air-suction elements are disposed radially relative to thehub portion of the surface element with the axes of said memberssubstantially tangential to the hub portion.

3. A centrifugal fan, comprising a baflle surface element with a hubportion, and a plurality of sets of spaced interfitting airsuctionelements on one face of the surface element surrounding the hub portionand each air-suction element including spaced inner and outer members,the members of each pair of said air-suction elements having wallscurved approximately similar to the curvature of a slitted tube and theedges of the slits being fastened to surface element whereby all of theairsuction elements are disposed radially relative to the hub portion ofthe surface element with the axes of said members substantiallytangential to the hub portion, the outer parts of the edges of the endsof the members of each pair of the air-suction elements being taperedtoward the centers of the lengths of the members as well as taperedtoward the hub portion of the surface ele ment.

4-. A centrifugal fan, comprising a disk with a hub portion, and aplurality of spaced pairs of blades fixed on one face of the disksurrounding the hub portion and each blade including spaced inner andouter members,

the members of each pair of said blades curved approximately similar tothe curvature of a slitted tube and the edges of the slits beingfastened to the surface element by a common means, and all of the bladesbeing disposed radially relative to the hub portion of the disk wherebythe axes of said blades are substantially tangential to the hub portion.

A. centrifugal fan, comprising a disk with a hub portion, a plurality ofspaced pairs of blades fixed on one face of the disk surrounding the hubportion each blade in eluding spaced inner and outer members, themembers of each pair of said blades curved approximately similar to thecurvature of a tube, and all of the blades being disposed radiallyrelative to the hub portion of the disk whereby the axes of said bladesare substantially tangential to the hub portion, the outer parts of theedges of the ends of the members of each pair of blades being taperedtoward the centers of the lengths of the blades as well as taperedtoward the hub portion of the disk.

6. A centrifugal fan, comprising a disk with a hub portion, and aplurality of spaced pairs of blades on one face of the disk surroundingthe hub portion and each blade including spaced inner and outer members,the members of each pair of said blades having walls curvedapproximately similar to the curvature of a slitted tube and the edgesof the slits being fastened to the disk whereby all of the blades aredisposed radially relative to the hub portion of the disk with the axesof said members substantially tangential to the hub portion, and a bandsecured on the outer faces of all of the outer members of the blades.

7. A centrifugal fan, comprising a disk with a hub portion, a pluralityof spaced pairs of blades on one face of the disk surrounding the hubportion, each blade including spaced inner and outer members and themembers of each pair of said blades hav- .ing walls curved approximatelysimilar to the curvature of a slitted tube and the edges of the slitsbeing fastened to the disk whereby all of the blades are disposedradially relative to the hub portion of the disk with the axes of saidmembers substantially tangential to the hub portion, the outer parts ofthe edges of the ends of the members of each pair of the blades beingtapered toward the centers of the lengths of the memhere as well astapered toward the hub portion, and a band secured on the outer faces ofall of the outer members of the blades.

8. A centrifugal fan comprising a disk, a ring spaced forwardly of thedisk and a plurality of tubular blades interposed between the disk andring, a second tubular blade within each of the first mentioned bladesand connected therewith.

This specification signed and witnessed this 29th day of May A. D. 1923.

ADOLPH F. ROTH.

Witnesses:

R. M. lVALKER, FREDERICK MYER.

